Field of the Invention
The present invention relates to a control device for controlling a sheet conveyance operation during printing, a method for controlling the control device, and a storage medium.
Description of the Related Art
In a printing apparatus, a difference in the distance to convey a sheet to a printing unit may cause a variation in the print start position of the sheet. In both-sided printing, after printing is executed on the front side, the sheet is turned to the back side and conveyed through a conveyance path for back-side printing. If a displacement of the sheet occurs in the direction orthogonal to the conveyance direction of the sheet while the sheet is conveyed for the back-side printing, there arises a problem that the print positions of the front side and the back side are different from each other. Such a positional displacement between the front side and back side occurs because a minute tilt of the sheet caused when the sheet has been stacked increases as the sheet is conveyed through the conveyance path. Therefore, Japanese Patent Application Laid-Open No. 2004-338119 discusses an image forming apparatus capable of correcting the print start position of an image based on a positional displacement amount of a recording medium.
However, in the image forming apparatus described in Japanese Patent Application Laid-Open No. 2004-338119, detection of a sheet edge position in a main scanning direction is executed on all sheets (i.e., on a sheet-by-sheet basis) when a front-side conveyance operation and a back-side conveyance operation are executed. Therefore, detection time is required after the front-side feeding operation and also after the back-side feeding operation, and this takes a longer time for the print operation.
Further, in a printing apparatus including a plurality of sheet feeding cassettes, the upper and lower sheet feeding cassettes are different from each other in the length of the conveyance path to the printing unit, for example, and a sheet fed from a sheet feeding cassette having a longer conveyance distance is more likely to cause a displacement in the direction orthogonal to the conveyance direction. However, in Japanese Patent Application Laid-Open No. 2004-338119, only a correction method for a single sheet feeding cassette is described.